Pedal operated stool or similar device



May 5, 1959 T. M. DE FORE 2,884,989

PEDAL OPERATED STOOL 0R SIMILAR DEVICE Filed May 5, 1955 INVENTOR. fi o/ms M D: F525 BY W M 6m Unite This invention relates to improvements in a pedal operated stool or similar device. In general the invention is concerned with a device which is adjustable in height and wherein the adjustment is foot operated to avoid the necessity of using the hands in producing the operation. In particular the stool or similar device is intended for use by surgeons or other technicians whose hands are in an aseptic condition or otherwise occupied in delicate work and wherein provision for change in elevation may be accomplished by the feet.

When a surgeon or other medical technician is preparing for a surgical operation, his hands must be in an aseptic condition, and in general all of the facilities provided in a hospital or surgeons oflice for use other than in directly conducting the operation will be of a pedal operated nature so that his hands do not become contaminated with micro-organisms existing on all nonsterile objects. In conducting numerous forms of examinations or operations, the surgeon is often seated for steadiness and comfort, but the nature of the work may require variation in position or elevation of his body. Once his hands are in an aseptic condition he can no longer touch any article of furniture or equipment that is not sterile, and therefore it is impossible for him to make an adjustment of the ordinary type swivel stool. Moreover, it is a general practice during the con-duct of a surgical operation to maintain an aseptic zone about the operating table, and no person who is not in an asceptic condition is permitted to enter the zone for any purpose whatsoever. Likewise, persons assisting the sur- 'geon must also be in an aseptic condition, and they cannot continue to assist him if their hands are brought into contact with any article that is not in an aseptic condition, and therefore none of the operating personnel may assist the surgeon in adjusting the height of a stool or similar device if any manual action is involved.

In the present invention I have provided a stool or similar device for use by surgeons or other technicians who desire or need provision for pedal operated adjustment of the height or position of the seat portion. The stool embodies a base containing a stationary upright portion formed with a spiral thread that coacts with a spirally threaded stem depending from the seat portion. The stem is provided with one or more vertical keyways. A pedal operated portion normally positioned adjacent the base and journalled thereon is provided with one or more keys that engage the keyways of the stern and are thus capable of rotating the stem by foot power to thereby provide vertical adjustment of the stem and connected seat without the necessity of touching any portion of the device with the hands. The pedal operated portion preferably assumes the shape of a disk overlying the base so that the user can make adjustment with the aid of either foot. If it is desirable that the device be made for adjustment either by the hands or feet, and this arrangement is sometimes desirable for office use as contrasted with operating room use, the seat is rigidly secured tates Patent C re 2,884,989 Ce et e a 5., 59

2 to the stem portion and therefore permits adjustment the normal rotativc manner by the hands.

An object of the invention is to provide a stool or similar device embodying vertical adjustment, accomplished by pedal operated means.

Another object is to provide a stool or similar device embodying vertical adjustment, in which the adjustment may be made either bythe hands orby the feet when it is not practical to use the hands.

A further object is to provide in a device of the class described, a base formed with an upright stationary member containing a spiral thread and adapted to re.- c eive'a coacting threaded member that contain s a vertical keyway, together with a pedal operated member journalled on the base and containing a key that engages the keyway and is capable of producing relative movement between the threaded members by pedal operation.

Other and further objects may become apparent from the following specification and claims, and in the appended drawing in which: j 2

Fig. 1 is a side elevation of a stool or similar device embodying the present invention, with portions shown in section; and, i

Fig. 2 is a plan view taken on line 2+2 of Fig. 1, look:- ing in the direction of the arrows. i

Referring now to the drawings, the invention will be described in detail. Reference character 5 indicates a fioor engaging base which is here shown as a pedestal. Extending upright from the base 5 is a tube 6 which has been secured to base 5 in a stationary manner. Any means may be used to rigidly join the lower end of tube 6 to base 5, and as shown a plug 6d composed of an expansible material such as wood and secured within the interior of the tube is joined to base 5 by an expansion plug 7. The uprightmember 6 has secured to its outer surface in spaced relation to each other a lower bearing or bushing 8 and an upper bearing or bushing 9. Merit-.- her 6 has press fitted into its upper end an internally threaded collar 10. A platform or seat portion ll has secured to its lower surface a flange 12 to which is rigidly secured an externally threaded stem 13. 'Stem 13 is provided with a pair of vertical keyways 14' extending transversely to the threaded portion. The stem 13 normally engages the internally threaded collar 10 of tube 6 and is rotatable with respect to the tube to change the elevation of seat 11. l V i A pedal operated disk 15 is positioned above the base 5 and is journalled thereon by a ball bearing race 16 located between a pair of washers 17 and 18 to give relatively frictionless movement of the disk 15 relative to base 5 and the lower portion of tube 6. Disk 15 is secured to a tube 19 that engages the upper and lower bearings or bushings 8 and 9 on tube 6. At its upper end tube 19 is closed by a disk 20 that contains a pair of keys 21 that are adapted to extend into the keyways 14 of stem 13.

In construction and operation tube 6 is secured onto base 5, and the seat 11 with stem 13 is threadedly engaged with the internal threaded collar 10, and provided seat 11 is rigidly secured to stem 13, elevation may be obtained in a conventional manner by manually rotating the seat 11. The pedal operated portion which includes disk 15, tube 19 and the keys 21 provide an alternate method of producing relative movement between stem 13 and tube 6 and the seat 11 may be raised or lowered by pedal movement of the disk 15.

In practice, if the user desires to change the elevation of platform or seat 11 it is necessary to arise therefrom and using either foot on disk 15 to rotate the same in either direction for purposes of elevating or lowering the seat. While the seat 11 is shown as being rigidly connected to stem 13, if necessary a ball bearing joint can be provided and in that instance elevation is accomplished only by means of disk 15 and its coacting parts. For use in a hospital operating room it is desirable that elevation be accomplished only by the pedal operated disk, in which case a bearing race will form the connection between the seat and the stem, but frequently in a doctors office it may be desirable to provide for alternate adjustmerit by the hands or feet, and in that instance the connection between seat 11 and stem 13 is a rigid fixed connection.

The advantage of the invention resides in the provision "of a structure of the class described in which elevation may be obtained by a simple mechanism which is certain in operation and permits the user to readily make adjustment by the use of either foot. Its advantage in conjunction with its preferred use in hospital operating rooms :or medical treatment rooms resides in the fact that adjustment is by the feet and does not require the user to touch any portion thereof, particularly when his hands are occupied or are in an aseptic condition.

The invention has been disclosed in the present specificationand drawings as applied to a pedestal type stool, but it is Within the spirit of this invention that it may be applied to stools or chairs of somewhat varying characteristics, and possibly to other structures of this general nature used in hospital operating rooms requiring adjustment in elevation of a platform or the like during an operation, and therefore the invention is not limited ,to the exact disclosure, but is defined in the terms of the appended claims. I claim:

1. A stool, comprising a base, an upright stationary tube carried by the base and formed with an internal .spiral thread adjacent the upper end thereof, a seat, a depending rod carried by the seat and formed with an external thread engaging the threaded portion of the tube and providing relative movement of the seat with .respect to the base, a vertical keyway formed in said rod, a second tube journalled on the first named tube and formed with a key extending into the keyway of said rod, and a foot operated member secured to said second tube adjacent the base for rotating the rod and adjusting the relative position of the seat.

2. A surgeons stool, comprising a pedestal base, a stationary upright tube carried by said base and formed with an internal spiral thread adjacent the upper end thereof, a seat, a depending rod rigidly secured to said seat and formed with an external spiral thread engaging the threaded tube and providing relative movement between the seat and the base, said rod formed with a pair of oppositely disposed keyways extending vertically through the threaded portion thereof, a second tube circumscribing the first named tube and formed with a pair of oppositely disposed keys adjacent the upper end thereof which engage in the keyways of said rod, and a pedal operated member journalled on the pedestal and secured to said second tube providing a foot operated means of adjusting the position of the seat.

3. In a device of the class described, in combination, a stationary member including an upright portion, said upright portion formed with a spiral thread extending downwardly from the upper end thereof, a cylindrical member formed with a spiral thread engaging the thread on the upright portion of said stationary member for movement relative thereto, said cylindrical member formed with a keyway therein extending generally transverse to the spiral thread, and a pedal operated member journaled on said stationary member and formed with a key engaging the keyway in said cylindrical member for rotating said cylindrical member relative to said stationary member and thereby varying the position of said cylindrical member with respect to the upright portion of said stationary member.

4. In a device of the class described, in combination, a stationary member including an upright tubular por tion formed with an internal spiral thread extending downwardly from the upper end thereof, a platform member including a rod depending therefrom, said rod formed with an external spiral thread engaging the'internal thread on the upright tubular portion of said stationary member for movement relative thereto, said depending rod formed with a keyway extending vertically through the spiral thread, a second tubular member encompassing the upright tubular portion of the stationary member and formed with a key extending into the keyway of the rod depending from said platform member, and a pedal operated member rigidly connected to said second tubular member for providing relative movement between the platform member and the stationary member to thereby vary the position of said platform member with respect to said stationary member.

References Cited in the file of this patent UNITED STATES PATENTS 12,972 Stratton May 2a, 1845 426,323 Purdy Apr. 22, 1890 2,224,543 Harmon Dec. 10, 1940 

